Implantable cardiac rhythm management (CRM) systems, including pacemakers, implantable cardioverter/defibrillators (ICDs), and cardiac resynchronization therapy (CRT, CRT-D) devices have been used to deliver effective treatment to patients with serious cardiac arrhythmias. In particular, rate adaptive pacing systems are known which utilize data obtained from various implanted sensors to adjust pacing parameters in response to increased patient demand.